[LEAPSECS] timekeeping resources for 2024?
Happy Holidays, I started to reply to recent emails, but all issues except one have been discussed over and over again on the mailing list and at the various workshops. So, my Christmas gift to you all is not to reply, and to myself was to dust off the login and server info for the futureofutc.org site (it has passed through a succession of web hosting companies and tech suites). I have updated the links for the presentations, discussions, and preprints for the 2011 and 2013 workshops to point away from the original lost host at Caltech. The 2014 session at the American Astronomical Society meeting is thrown in for good measure: http://futureofutc.org http://futureofutc.org/2011 http://futureofutc.org/aas223 Please advise of any remaining broken links (some of the 3rd party links have gone stale, for instance) and suggest additional online resources to add to a new 2024 links tab. Folks with institutional access might want to also download the proceedings from “The Science of Time 2016”: https://ui.adsabs.harvard.edu/abs/2017ASSP...50.A/abstract For example, see chapter 28: “How Gravity and Continuity in UT1 Moved the Greenwich Meridian”, by Malys, Seago, Pavlis, Seidelmann, and Kaplan. The one issue that has not been sufficiently addressed is the standards, protocols, funding, and logistics for future infrastructure supporting mean solar time now that UTC won’t. (UT1 is an observational time scale that is only known a couple of months after the fact.) Perhaps significant work has been done recently on these infrastructure issues. Pointers would be welcome. Other custodians of civil time resources are encouraged to review and enhance them in 2024. Best wishes to all in the New (leap) Year! Rob Seaman Lunar and Planetary Laboratory University of Arizona ___ LEAPSECS mailing list LEAPSECS@leapsecond.com https://pairlist6.pair.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] UT1 offset
Let’s back of the envelope the impact of a 1 second error in a longitude sight. The Sun moves 360 degrees in 86400 seconds. A one second error is then about 0.004 degree. But in equatorial km, let’s assume 40,000 km circumference, so 40,000 km in 86,400 seconds (yeah, it’s actually less, sidereal day and all that). Or an error of about 1/2 km. For the vast majority of boat driving purposes, this is sufficiently accurate - you need to get to within visual range of the coast, so you can get into the desired port. For flying a plane by celestial navigation, you might care more, because the plane is flying faster than a boat moves. Sent from my iPad > On Dec 26, 2023, at 7:10 AM, Gary E. Miller wrote: > > Yo Hal! > >> On Mon, 25 Dec 2023 00:25:07 -0800 >> Hal Murray wrote: >> >> Who uses DUT1 via radio? Who will be using it 50 years from now? >> >> Is it needed for anything other than navigation and astronomy? > > I just asked my brother that did a lot of transoceanic navigation > by sextant. He did not even know what UT1 is. He certainly would > not know what to do with DUTs. > > RGDS > GARY > --- > Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703 >g...@rellim.com Tel:+1 541 382 8588 > >Veritas liberabit vos. -- Quid est veritas? >"If you can't measure it, you can't improve it." - Lord Kelvin > ___ > LEAPSECS mailing list > LEAPSECS@leapsecond.com > https://pairlist6.pair.net/mailman/listinfo/leapsecs ___ LEAPSECS mailing list LEAPSECS@leapsecond.com https://pairlist6.pair.net/mailman/listinfo/leapsecs
